taylor etal



March 1964 A.- s. TAYLOR ETAL 3,

CAPSULE FORMING DIE ROLL WITH GUARD RINGS 3 Sheets-Sheet 1 Filed March5, 1962 \N MN Arthur Sinclair Taylor William Peter Konuzewski WWW/away AT TOR/YE Y March 1964 A. s. TAYLOR ETAL 0 CAPSULE FORMING DIE ROLL WITHGUARD RINGS Filed March 5, 1962 3 Sheets-Sheet 2 Hihii:

INVEN TOR. Arthur Sinclair Toylor William Peter Konozewski A T TOR/V5 YMarch 17, 1964 A. S. TAYLOR ETAL CAPSULE FORMING DIE ROLL. WITH GUARDRINGS Filed March 5, 1962 3 Sheets-Sheet 3 INVENTOR. Arthur SiIIOIOlITaylor William Peter Konozewski BQMWLWMM ATTORNEY United States PatentOfiice Patented Mar. 17, 1964 3,124,840 CAPSULE FORMING DIE ROLL WITHGUARD RINGS Arthur fiinclair Taylor, Spring Valley, and William P.

Konazewslri, Pearl River, N.Y., assignors to American Cyanamid Company,New York, N.Y., a corporation of Maine Filed Mar. 5, 1962, Ser. No.177,365 7 Ciaims. (Cl. 18-21) This invention relates to improvements indie roll construction for the encapsulation of materials such aspharmaceutical products in a soft plastic film such as gelatin films,and more particularly, to asymmetric die rolls in which the cavity dieroll has guard rings at each side of the working face with which theseal roll is in constant rolling contact, to space the roll system,minimize vibration, and reduce the wear on the cutting out rims of thecapsule forming cavities; and to a hinged die roll frame to permit rapidexchange of the rolls.

Soft gelatin capsules have been formed on roll systems involvingasymmetric die rolls as disclosed in more detail in United States Patent2,663,128, F. E. Stirn and A. S. Taylor, Method and Machine for MakingCapsules, December 22, 1953; United States Patent 2,624,164, A. M.Donofrio, Method of and Apparatus for Encapsulating Liquid andSemiliquid Substances and the Like, January 6, 1953; United StatesPatent 2,663,129, A. M. Donofrio, Machine for Fabricating Capsules FromElastic Films, December 22, 1953; and United States Patent 2,775,080, F.E. Stirn and A. S. Taylor, Method of Forming Powder-and-Liquid FilledCapsules, December 25, 195 6. Die rolls for such encapsulating machinesare disclosed in United States Patent 2,697,317, F. E. Stirn and A. S.Taylor, Capsule Forming Die Roll, December 21, 1954, and United StatesPatent 2,799,048, F. E. Stirn and A. S. Taylor, Die Roll forEncapsulating Machine, July 16, 1957.

The die roll system of the present invention can be used in otherencapsulation machines; and may be used for plastic materials other thana gelatin-glycerine-water composition, although such composition ispresently meeting with the greatest commercial acceptance. The films arecast as a strip, fed to the machines, and will hereafter be calledplastic strips.

Cavity die rolls have, in general, been formed with at least two andoften three or more rows of die cavities.

It has now been found that one or two rows of die cavities may be usedfor production purposes by providing the cavity die roll with guardrings with which the seal roll is in constant rolling contact, thusinsuring uniformity of spacing between the die roll and the seal rolland preventing rocking, or wobbling, from unsymmetrical and irregularforces, which necessarily result from the contact of the seal roll withthe rims of the die cavities where one or two rows of die cavities aloneare present in the cavity die roll. By having the guard rings to insurean essentially and basically stable and symmetrical system, difficultieswith die alignment, bearing wear, lost motion and uneven driving areminimized, and at the same time the useful life of the cutting-out rimson the die cavities is markedly increased. Less rigorous requirementsfor rigidity of roll axle supports permits a design permitting morerapid die roll interchange.

The guard rings and the cutting-out rims may be integral with the cavitydie roll blank, but it is easier to machine the roll assembly if a blankof softer material is used and the capsule cavity inserts and the guardrings are of a hardened material such as hardened steel. Naturally, theguard rings should fit tightly on to the die roll.

The one or two row cavity die roll is particularly useful for largecapsules and also permits the building of a smaller encapsulationmachine using a smaller casting roll so that the entire machine is moreconveniently portable and may be moved and reset up for operation with amaximum of convenience and a minimum of time. For small runs, it isdesirable that a smaller sized machine be used so that the relativewaste in threading the machine and starting up and stopping is at aminimum. A smaller machine may be more easily controlled by oneoperator, thus reducing labor costs.

Additionally, by having guard rings to reduce vibration and wobbling,there is less wear on the bearings and the maintenance to eliminate lostmotion in the roll system is minimized. In smaller machines a morecompact housing may be used so that only the interior of the castingwheel should need be air conditioned and the air conditioning load isthus lessened.

The guard rings are beveled on the side towards the capsule formingcavities, which helps to guide the plastic strip towards the workingarea.

For ease in changing from one die roll to another die roll, so as topermit diiferent sizes of capsules to be run, the die roll and itsmating seal roll and the filling system, which may include a measuringroll operated in timed relationship with the cavity die roll, aremounted in a die roll frame, consisting of two spaced plates, which arehinged to the main frame of the machine so that the rolls may be swungout for ease of access. It is preferred that each of the cavity dieroll, the seal roll, and the measuring roll be independently joumaled ina bearing casing so that the roll shafts, with drive gears, andassociated parts, may be inserted into slots in the hinged die rollframe. Thus by swinging out the die roll frame each of the rolls may bereleased rapidly to permit ready replacement.

The remainder of the machine may follow conventional practice. Withoutundue prolixity and detail on parts of the encapsulation machine whichare not essentially novel with the present invention, and without unduerecitation of obvious modifications, embodiments of the presentinvention are shown in the accompanying drawings in which:

FIGURE 1 is an axial view of a die roll and the valve plates.

FIGURE 2 is a cross-section on line 2-2 of FIGURE 1 showing the die rolltogether with the associated valve plates in section, for a die rollwhich has a single row of capsule forming cavities.

FIGURE 3 is a cross-section view of a die roll with associated valveplates and the die roll shaft and bearing casings for a die roll havingtwo rows of capsule forming cavities.

FIGURE 4 is a view of a part of the face of a die roll having two rowsof capsule forming cavities, such as shown in FIGURE 3.

FIGURE 5 is a view of a part of the face of a die roll having a singlerow of capsule forming cavities, such as shown in FIGURE 2.

FIGURE 6 is a front view of the complete encapsulation machine.

FIGURE 7 is a partial-top View of an encapsulation machine showing ahinged die roll frame.

The Die Roll System As shown in FIGURES 1 and 2, the die roll 11 may bebuilt up from a cylindrical cavity die roll blank 12, convenientlyturned from a cylinder of manganese bronze. The die roll has a die rollhub 13 in which is the hole 14 for the die roll shaft 15. A keyway 16 isprovided for a key 17 to hold the die roll hub in position on the dieroll shaft. Tapped holes 18 are provided for scews to hold the die rollhub firmly in position on the die roll shaft. In the die roll blankperiphery 19 are a series of insert slots 20. A capsule cavity insert21, preferably of hardened steel fits in each insert slot 20. Under theinsert there is at least one capsule ejector plug 22 on the head ofwhich, towards the axis of the die roll, is a capsule ejector piston 23in a capsule ejector piston cylinder 24. The capsule cavity insert 21may be held in position in the insert slot by an insert screw 25. Fromthe bottom of the capsule ejector piston cylinder runs a manifoldpassage 26 to a valve seat surface 27 of the die roll.

Additional details of such a die roll system, including certainmodifications, are described at length in United States Patents2,697,317 and 2,799,048, supra.

The valve seat surface is inset from the fiat ends 23 of the die roll.This provides additional clearance for the valve plates 29, reduces theweight of the die roll, and gives an inset valve seat surface 2'7 whichis thus more protected from damage during handling and, additionally,the inset helps to divert any powder or capsule contents or other dustaway from the valve seat surface, thus giving longer operation beforethe die roll and valve plates must be disassembled for cleaning. Thevalve plates conveniently, but not necessarily, are coaxial with the dieroll hub 13 and are positioned by sliding on the hub. In the valveplates, adjacent to the valve seat surface of the die roll are thevacuum chests 30 to control the vacuum for holding the capsule ejectorpiston and its associated plug at the bottom of the capsule ejectorpiston cylinder. Vacuum to this chest is provided by a vacuum connection31. Also connected to this vacuum chest is a balancing chamber 32 whichbalances the vacuum around the valve plate so that the vacuum forces aremore nearly equalized. A holddown vacuum chest 33 provides for vacuum tothe holddown bleeds 34, which are a series of small holes drilled in theperipheral face of the die roll outside of the capsule cavity insertswhich supply vacuum to hold the plastic strip outside of the capsulecavity inserts against the face of the die roll. The capsule ejectorplug and the capsule ejector piston fit loosely under the capsule cavityinsert so that part of the vacuum operating the piston leaks past thepiston and plug and holds the plastic strip interiorly of the capsulecavity insert while the capsule contents are being filled. A gap 35exists between the vacuum chest 3t and a capsule retaining vacuum chest36 which is in such position as to hold the capsules in the cavitieswhile the residual web is being stripped. A pressure chest 37 suppliedwith air by a pressure connection 38 blows the pistons, and the plugs,away from the axis of the roll, thereby ejecting the finished capsules.

Around the die roll blank periphery are the guard rings 39.

Preferably the guard rings are of hardened steel, tightly fitted to thedie roll blank. In manufacture, it is convenient to grind thecylindrical peripheral face 46) of the guard rings and the capsulecavity insert rim face 41 in a single operation on a grinding machine sothat the faces are smooth, polished, and concentric. Thus in operationthe seal roll 42 (note FIGURE 6) rolls on the peripheral face 40 of theguard rings and just touches the rim faces of the capsule cavityinserts. Thus there is a uniform rolling contact at all times betweenthe seal roll and the cavity die roll.

As shown in FIGURE 1, the valve plates 29 are positionedcircumferentially by a positioning bracket 43 so that the exact angularlocation of the release of vacuum for the sealing operation can becontrolled.

The surface of the roll shown in FIGURE 2 is illustrated in FIGURE whichshows a single row of capsule cavity inserts for long oval capsules.

In FIGURE 4 is shown a similar die roll but with two rows of capsulecavity inserts for elliptical or football shaped capsules, technicallytermed a prolate spheroid, or a reasonably accurate facsimile thereof.

In FIGURE 3 is shown the sectional view of the die roll for a double rowof cavity inserts. Inasmuch as the configuration is essentially thesame, except for the the number and spacing of the cavity inserts, theconstruction is not repetitively described in detail. Two

active valve plates are used for the multiple row die rolls. Only oneactive valve plate is needed for single row die rolls.

The die roll itself may have capsule cavity inserts of the types shownin the various modifications illustrated in United States Patents2,697,317, or 2,799,048, supra, or even as modified in United StatesPatent 2,902,802, F. E. Stirn and A. S. Taylor, Encapsulating Die RollSystem, September 8, 1959.

The die roll is positioned on a die roll shaft 15. The die roll hub 13is held against a collar 44 by a retaining nut 45. On the shaft spacedfrom the die roll are two bearing casings 46. These may be the exteriorraces of roller or ball bearings or conveniently are annular sleevescontaining anti-friction bearings. Each bearing casing has a smallflange 47 on each side thereof. The assembly complete with shaft isconveniently treated as an interchangeable assembly and changed as aunit in the encapsulation machines, although the same shaft may be usedin a plurality of die rolls. If the same shaft is used, it takes a fewminutes longer to change the die rolls but there are no otherdisadvantages.

The Encapsulation Machine The encapsulation machine is shown in FIGURE6. The main part of the encapsulation machine is above a table 43.Conveniently this table is a rigid plate of metal such as aluminum or analuminum alloy. The exterior of the table, beneath the table, isenclosed by a skirt 49. In the area beneath the table and enclosed bythe skirt can be placed associated elements such as a vacuum pump, anair pressure pump, the drive mechanisms and the cooling assembly, whichmay be a compressor-type refrigeration unit for the strip casting wheel.Such details are conventional and within the skill of the art. Above thetable is a main frame 50. Mounted on one end of the table is a castingwheel 51 on which the strip material, such as gelatin, is cast from ahopper 52. The Wheel is preferably cooled by refrigeration so that thewheel is at a preferred temperature for the casting operation.Exteriorly of the wheel is a shroud 53. For a gelatin film a cool dryair is blown into the shroud to dry and chill the surface of the gelatincomposition as cast. For other plastic compositions, the temperature andhumidity are controlled to give an environment desired for thatparticular plastic material. The front face 54 of the shroud is used asan instrument panel and thereon are mounted pressure and temperaturegauges, air pressure, and vacuum control valves, pump control switches,speed controls, and auto transformers for controlling the heat input tovarious elements of the machine.

Also on the main frame are mounted guide pulleys 55 for controlling thepath of the cast plastic strip, which strip may be passed over the guidepulleys or may rest on conveyor belts 56 which in turn rest on thepulleys. Conveniently, all such guide pulleys on which the strip restsand all conveyor belts are power driven to avoid stretching the strip.Also mounted on the main frame is an inside coater 57, an assembly whichpro vides a coating such as a beta pinene polymer or other protectivematerial on the surface of the strip which is to become the interior ofthe capsules. A strip oiler 58 coats the outside of the strip, which isto contact the cavity die roll, with a lubricant. A turnover roll system59 reverses the top strip and moves it laterally to feed it into face toface relationship with the lower plastic strip, with the surfaces whichwere in contact with the casting drum in face to face relationship toform the interior of the capsules. Space is provided for a printingelement 69 which may be added to the machine to print on the top orbottom plastic strips or both in timed relationship with the cavity dieroll where a printed legend is desired on the surface of the capsules.

With this much equipment on the face of the main frame, various elementsinterfere with free access to the die roll system. A pair of spacedplates, including a front spaced plate 61 and a rear spaced plate 62 aremounted on hinges 63, which hinges are attached to the main frame 58.The spaced plates are held apart by tubular separators 64 from the dieroll frame and are held in position on the main frame by bolts 65passing through the tubular separators. Thus the spaced plates arefirmly and fixedly in position with relationship to the main frame; butby loosening three bolts, the spaced plates may be pivoted away from themain frame so that the rolls may be changed more easily.

A separate pair of U-shaped slots are provided for each roll. The dieroll U-shaped slots 66 extend laterally to the left. The die roll on thedie roll shaft supported by the die roll bearing casings 46 slides intothe die roll U-shaped slots and is held in position by a die rollretainer 67, which conveniently is a U-shaped washer which turns inrelationship to the frame to lock the bearing casings in position. A setof lock nuts 68 and positioning screws 69 holds the positioning bracket43 in position and permits micro-metric angularly positioning of thevalve plates 29.

Extending to the right and upwardly is the seal roll U-shaped slots 70.In the seal roll U-shaped slots fits a seal roll 42, in the seal rollbearing casings 71. The seal roll is a roll which may have a smoothcylindrical surface or such other surface as may be desired whichpresses against and rolls on the surface of the peripheral face of theguard rings and the capsule cavity insert rim faces 41 of the die roll.A seal roll plate 72 fits against the front and rear spaced plates andsupports a spring bracket 73 which spring loads a seal roll retainer 74,which presses against retaining pins 75, which press downwardly againstthe seal roll bearing casings These are thus spring urged towards thedie roll to give the desired cutting out pressure between the seal rolland the cavity die roll. The seal roll may be heated, and have insertfaces or depressions to permit a preferred mating relationship betweenthe seal roll and the die roll, in accordance with conventionalpractices. Certain details of such a configuration are shown in UnitedStates Patent 2,674,073, A. S. Taylor and F. E. Stirn, Relieved Non-SkidSeal Roll and Meth- 0d of Use, April 6, 1954.

Above the die roll, and extending upward, are the measuring rollU-shaped slots 76. These slots open upward for a measuring roll 77mounted on a shaft in the measuring roll bearing casings 78 which areconveniently retained in position by drift pins 79 mounted in the frontand rear spaced plates. The measuring roll is of conventionalconfiguration for measuring a charge of powder or other material intothe strip lined capsule cavity inserts.

On the back side of the rear spaced plate are drive gears 80 which drivethe three principal rolls, the die roll, the seal roll, and themeasuring roll, in timed relationship. One of these gears is driven by adrive spur shaft 81. The drive mechanisms for all of the rolls isconveniently a roller chain passing over a set of sprockets inside ofthe main frame St).

The details of the various parts of the machine are in accordance withconventional practice and are not further explained in detail here toavoid unduly lengthening the description of the machine. The patentsabove referred to explain in more detail various parts of anencapsulation machine.

It is to be understood that the exact configuration of the associatedelements may be in accordance with other conventional practices withoutdeviating from the scope of the appended claims.

Furthermore, the die roll itself may be made by engraving or otherwiseforming a single piece of metal, as for example the guard rings, andcutting out rim faces 41 can be cut from billet stock of a suitablemetal. Bronze may be used for short runs, and a hardenable ,iaasao t5steel can be used in which the engraving and principal shapingoperations are done while the steel is soft, and then hardening thesteel with a final grinding operation to compensate for warpage duringhardening. The builtup die roll, as shown in the drawings, is normallythe most economical construction for commercial operations.

The use of various forming operations, plastic strip compositions,internal and external printing, coating, oiling, drying, and associatedoperations are apparent to those skilled in the art and may be used inconjunction with the present invention, which is defined in the appendedclaims.

We claim:

I. In a die roll for forming soft plastic capsules from plastic sheetmaterial which comprises: a substantially cylindrical die roll blank,having in the cylindrical periphery thereof a series of capsule-formingcavities, each consisting of a hardened-steel, raised-rim, capsulecavity insert fitted into an insert slot in the periphery of saidcylindrical roll and having at least one piston cylinder under saidinsert, at least one capsule ejector plug extending towards the insertcavity in the insert, said capsule ejector plug having thereon a capsuleejector piston, fit ting in said cylinder, whereby said plug may be, byair pressure, raised to substantially the top of said cavity, orretracted to form a portion of the bottom of said cavity, a manifoldpassage from adjacent the axial end of said cylinder to a valve surfaceof said die roll blank, whereby ir pressure, acting through adjacentvalve means at desired times during the rotation of the roll, causes anincrease or reduction in the pressure in said cylinder, therebyactuating said piston and plug;

the combination therewith of a separate continuous hardened steel guardring on each side of the periphery of said cylindrical die roll blankand concentric with said die roll, and of a diameter such that thegreatest diameter of the guard ring is substantially the same as andcoaxial with the diameter of the face of the cutting out rims of saidinserts.

2. In a die roll for forming soft plastic capsules from plastic sheetmaterial which comprises: a substantially cylindrical die roll blank,having in the cylindrical periphery thereof a series of capsule-formingcavities, each consisting of a raised-rim, capsule cavity insert fittedinto an insert slot in the periphery of said cylindrical roll and havingat least one piston cylinder under said insert, at least one capsuleejector plug extending towards the insert cavity in the insert, saidcapsule ejector plug having thereon a capsule ejector piston, fitting insaid cylinder, whereby said plug may be, by air pressure, raised tosubstantially the top of said cavity, or retracted to form a portion ofthe bottom of said cavity, a manifold passage from adjacent the axialend of said cylinder to a valve surface of said die roll blank, wherebyair pressure, acting through adjacent valve means at desired timesduring the rotation of the roll, causes an increase or reduction in thepressure in said cylinder, thereby actuating said piston and plug;

the combination therewith of a continuous guard ring on each side of theperiphery of said cylindrical die roll blank operationally integral withsaid die roll, and of a diameter such that the greatest diameter of theguard ring is substantially the same as and coaxial with the diameter ofthe face of the cutting out rims of said inserts.

3. In a cavity die roll for forming soft plastic capsules from plasticstrips which comprises: a substantially cylin drical die roll blankhaving a plurality of slots in the periphery thereof, at least onecapsule ejector piston cylinder in the bottom of each slot, a pluralityof capsule ejector plugs, one for each of such cylinders, a capsuleejector piston attached to each of such capsule ejector plugs andslidable in the capsule ejector piston cylinder, a capsule cavity insertin each of said slots, said capsule cavity inserts having in the bottomthereof an opening for said plug, said pistons and said plugs fittingloosely in areas 1o 6 said cylinder and said opening, a cutting out rimon each insert extending above the surface of the die roll blank withthe faces of such cutting out rims forming portions of a cylindricalsurface concentric with the axis of the die roll, and a manifold meansextending from the lower portion of each of said capsule ejector pistoncylinders to a valve surface of said roll, whereby a vacuum may act on aplastic strip to draw it into the capsule cavity inserts, and an airpressure can act to raise the piston, the plugs, and eject the capsules;

the combination therewith of a continuous guard ring on each side of theperiphery of said cylindrical die roll blank, and of such a diameterthat the greatest diameter of the guard ring is substantially the sameas and coaxial with the diameter of the faces of the cutting out rims ofsaid inserts.

4. In a cavity die roll for forming soft plastic capsules from plasticstrips which comprises: axle means for a capsule forming cavity dieroll, a substantially cylindrical capsule forming die roll having aplurality of capsule forming cavities in the periphery thereof, gascontrolled ejector means for each such cavity, each cavity having acutting out rim extending around the periphery of the capsule-formingcavity and said rim being the same distance from the axis of the dieroll at all points;

the combination therewith of a guard ring on each side of the peripheryof said die roll extending continuously circuniferentially around saidperiphery and essentially concentric with and of the same diameter asthe cuttin out rims of the capsule-forming cavities.

5. In a cavity die roll assembly for forming soft plastic capsules fromplastic strips and which permits rapid roll interchange which comprises:a die roll shaft, a substantially cylindrical capsule forming die rollhaving a plurality of capsule-forming cavities in the periphery thereof,gas controlled ejector means for each such cavity, each cavity having acutting-out rim extending around the periphery of the capsule-formingcavity and the face of said rim being the same distance from the axis ofthe die roll at all points;

the combination therewith of a guard ring on each side of the peripheryof said die roll extending continuously circumferentially around saidperiphery and essentially concentric with and of the same diameter asthe faces of the cutting-out rims of the capsuleforming cavities, meansto attach the die roll to said shaft, and a bearing casing rotatablymounted on said shaft on each side of the die roll, whereby the rollassembiy can be rapidly interchanged in slots in the frame of anencapsulation machine.

6. An encapsulation machine comprising: a main frame, a die roll framecomprising two spaced plates, separators for said plates holding saidplates in fixed parallel relationship to each other, and parallel to themain frame in operating position, hinges between said plates and saidmain frame, to permit the die roll frame to be swung out from the mainframe for easy and rapid interchange of roll sets, bolts to fixedlysecure the die roll frame to the main frame, at least two sets ofU-shaped slots in said die roll frame, a set of die roll bearingcasings, a cavity die roll rotatably mounted therein, means to lock thedie roll bearing casings in position in one set of said U-shaped slots,a set of seal roll bearing casings, a seal roll rotatably mountedtherein on an axis perpendicular to the frames, and means to removablyposition the seal roll in position in the second set of U-shaped slotsand spring load the seal roll against the die roll.

7. An encapsulation machine comprising: a main frame, a die roll framecomprising two spaced plates, separators for said plates holding saidplates in fixed parallel relationship to each other, and parallel to themain frame in operating position, hinges between said plates and saidmain frame, to permit the die roll frame to be swung out from the mainframe for easy and rapid interchange of roll sets, bolts to fixedlysecure the die roll frame to the main frame, at least two sets ofU-shaped slots in said die roll frame; a substantially cylindricalcapsuleforming die roll having a plurality of capsule forming cavitiesin the periphery thereof, gas controlled ejector means for such cavity,each cavity having a cutting-out rim extending around the periphery ofthe capsule-forming cavity and the face of said rim being the samedistance from the axis of the die roll at all points; a guard ring oneach side of the periphery of said die roll extending continuouslycircumferentially around said periphery and essentially concentric withand of the same diameter as the cutting-out rims of the capsule-formingcavities, a die roll shaft, means to attach the die roll to said shaft,and a die roll bearing casing rotatably mounted on said shaft on eachside of the die roll; means to lock the die roll bearing casings inposition in one set of said U-shaped slots, a set of seal roll bearingcasings, a seal rollrotatably mounted therein on an axis perpendicularto the frames, and means to removably position the seal roll in positionin the second set of U-shaped slots and spring load the seal rollagainst the die roll.

References Cited in the file of this patent UNITED STATES PATENTS309,118 Wilcox Dec. 9, 1884 538,475 Albrecht Apr. 30, 1895 899,087Walker Sept. 22, 1908 902,699 Nehorn Nov. 3, 1908 2,141,318 SalfisbergDec. 27, 1938 2,312,049 Pfeiffer Feb. 23, 1943 2,387,747 Crowley Oct.30, 1945 2,624,164 Donofrio July 6, 1953 2,663,128 Stirn et al Dec. 22,1953 2,708,287 Long et a1 May 17, 1955 2,902,718 Martelli et al Sept. 8,1959

1. IN A DIE ROLL FOR FORMING SOFT PLASTIC CAPSULES FROM PLASTIC SHEETMATERIAL WHICH COMPRISES: A SUBSTANTIALLY CYLINDRICAL DIE ROLL BLANK,HAVING IN THE CYLINDRICAL PERIPHERY THEREOF A SERIES OF CAPSULE-FORMINGCAVITIES, EACH CONSISTING OF A HARDENED-STEEL, RAISED-RIM, CAPSULECAVITY INSERT FITTED INTO AN INSERT SLOT IN THE PERIPHERY OF SAIDCYLINDRICAL ROLL AND HAVING AT LEAST ONE PISTON CYLINDER UNDER SAIDINSERT, AT LEAST ONE CAPSULE EJECTOR PLUG EXTENDING TOWARDS THE INSERTCAVITY IN THE INSERT, SAID CAPSULE EJECTOR PLUG HAVING THEREON A CAPSULEEJECTOR PISTON, FITTING IN SAID CYLINDER, WHEREBY SAID PLUG MAY BE, BYAIR PRESSURE, RAISED TO SUBSTANTIALLY THE TOP OF SAID CAVITY, ORRETRACTED TO FORM A PORTION OF THE BOTTOM OF SAID CAVITY, A MANIFOLDPASSAGE FROM ADJACENT THE AXIAL END OF SAID CYLINDER TO AVALVE SURFACEOF SAID DIE ROLL BLANK, WHEREBY AIR PRESSURE, ACTING THROUGH ADJACENTVALVE MEANS AT DESIRED TIMES DURING THE ROTATION OF THE ROLL, CAUSES ANINCREASE OR REDUCTION IN THE PRESSURE IN SAID CYLINDER, THEREBYACTUATING SAID PISTON AND PLUG; THE COMBINATION THEREWITH OF A SEPARATECONTINUOUS HARDENED STEEL GUARD RING ON EACH SIDE OF THE PERIPHERY OFSAID CYLINDRICAL DIE ROLL BLANK AND CONCENTRIC WITH SAID DIE ROLL, ANDOF A DIAMETER SUCH THAT THE GREATEST DIAMETER OF THE GUARD RING ISSUBSTANTIALLY THE SAME AS AND COAXIAL WITH THE DIAMETER OF THE FACE OFTHE CUTTING OUT RIMS OF SAID INSERTS.